NEMD Lab., Department of Mechanical Engineering, Yonsei University, Seoul 120 749, Republic of Korea.
Nanoscale. 2013 Jun 21;5(12):5620-7. doi: 10.1039/c3nr00265a.
The role of palladium (Pd) in the reduction of graphene oxide (GO) thin films was investigated using a Pd assisted grafting technique. The structural and optical characteristics of these thin films were obtained from various spectroscopic analyses, which confirmed increased C[double bond, length as m-dash]C-C aromatic ring vibration and oxidation of Pd with Ar annealing. In Pd free GO, annealing of films resulted in restoration of sp(2) clusters; however, Pd grafting with non-annealed film enhanced the possibility of restoration and further annealing dramatically increased the restoration rate with enhanced blue photoluminescence (PL) emission. The blue PL emission originates from sp(2) cluster sites and the yellow-green PL from defect trapped states. As reduction of GO increased, yellow-green emission decreased and blue PL became the prominent emission. These experimental findings open up a new feasible pathway for controlling the luminescence emission from graphene oxide that furthers the technological advancement of graphene based optoelectronic devices.
采用钯辅助接枝技术研究了钯（Pd）在还原氧化石墨烯（GO）薄膜中的作用。通过各种光谱分析获得了这些薄膜的结构和光学特性，证实了随着 Ar 退火，C[双键，长度为 m-dash]C-C 芳环振动和 Pd 的氧化增加。在无 Pd 的 GO 中，退火导致 sp(2) 簇的恢复；然而，与非退火薄膜相比，Pd 接枝增强了恢复的可能性，进一步退火则大大提高了恢复速率，同时增强了蓝色光致发光（PL）发射。蓝色 PL 发射源于 sp(2) 簇位，而黄绿光发射则源于缺陷捕获态。随着 GO 的还原增加，黄绿光发射减少，蓝色 PL 成为主要发射。这些实验结果为控制氧化石墨烯的发光发射开辟了一条新的可行途径，进一步推动了基于石墨烯的光电设备的技术进步。
